Key-coupler for coupling key to key-holder

ABSTRACT

A key-coupler for coupling a key with a key-holder includes a first closed ring to which the key-holder is connected and a second closed ring to which the key is connected. The key-coupler is integrally made of a single spring wire and includes a pair of circular portions and a portion connecting the pair of circular portions. Both closed rings are formed by overlapping the pair of circular portions with each other. The key-coupler is easily opened by simply separating one circular portion from the other, and is closed by its own spring action upon removing a force separating the circular portions.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is based upon and claims benefit of priority of Japanese Patent Application No. 2002-268594 filed on Sep. 13, 2002, the content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a key-coupler for coupling a key or keys to a key-holder.

[0004] 2. Description of Related Art

[0005] A double looped key-coupler as shown in FIG. 12A has been well known hitherto. The key-coupler 70 is made of a spring wire. One end of the spring wire forming the key-coupler 70 is opened to insert the key-coupler 70 into a hole 21 of a key 20. Then, the key 20 is turned along the loop of the key-coupler 70 to be coupled therewith. The key coupler 70 may be further coupled with a key-holder (not shown), so that the key 20 is coupled to the key-holder via the key-coupler 70. Plural keys 20 may be similarly coupled to the key-holder.

[0006] Another well known key-coupler is shown in FIG. 12B. The key-coupler 80 is made in a triangular shape that has an opening. To couple the key-coupler 80 with the key 20, the opening of the key-coupler is forcibly opened, and the key 20 is inserted through the opening. Then, the opening of the key-coupler is forcibly closed again to keep the key 20 coupled with the key-coupler 80. The key-coupler 80 may be further coupled with a key holder (not shown) so that the key 20 is coupled with the key-holder via the key-coupler 80.

[0007] It is not so easy to couple or uncouple the key 20 with those conventional key-couplers 70, 80. In the double looped key-coupler 70, one end of the spring wire has to be forcibly opened against a spring action of the spring wire to couple the key 20 with the key-coupler 70. Then, the key 20 has to be rotated along the loop of spring wire. If coupling and uncoupling the key 20 with the key-coupler 70 are repeated many times, the spring action of the key-coupler 70 may be deteriorated, and the key-coupler 70 may become not to properly function. Further, in case the key 20 is made of a soft material such as resin, the key 20 may be damaged by the end of the spring wire. In the case of the key-coupler 80 shown in FIG. 12B, a tool may be required to open or close it because it is usually too hard to manually deform the key-coupler 80.

SUMMARY OF THE INVENTION

[0008] The present invention has been made in view of the above-mentioned problem, and an object of the present invention is to provide an improved key-coupler that is easily coupled or uncoupled with a key or keys.

[0009] The key-coupler according to the present invention includes a first closed ring and a second closed ring. A key or keys are connected to the second closed ring, for example, and a key-holder is connected to the first closed ring. Thus, the key or keys are coupled to the key-holder via the key-coupler. It is most preferable to make the key-coupler integrally from a single spring wire. The first closed ring is formed by overlapping a pair of circular portions, each having an opening that is closed with the other circular portion when circular portions are overlapped. The pair of the circular portions are connected to each other with a connecting portion. The second closed ring surrounded by the connecting portion is also formed when the pair of circular portions are overlapped.

[0010] By separating one circular portion from the other circular portion, both of the first and the second closed rings are opened at the same time. Upon opening the rings, a key or keys are inserted into the second closed ring, and the key-holder is inserted into the first closed ring. By releasing the separating force, both rings are closed due to a spring-back action of the spring wire that forms the key-coupler. Thus, the key or keys are coupled to the key-holder via the key-coupler. To remove the key from the key-coupler, both rings are opened by separating one circular portion from the other. A small gap may be formed between the pair of circular portions, so that the overlapped pair of circular portions are easily separated by pushing a back of a key against the small gap.

[0011] A key or keys are easily coupled or uncoupled with a key-holder via the key-coupler according to the present invention. The key-coupler is easily opened or closed by simply separating one circular portion from the other, and the key-coupler can be repeatedly used for a long time without being deformed. Other objects and features of the present invention will become more readily apparent from a better understanding of the preferred embodiment described below with reference to the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIGS. 1A-1D are a front view, a top view, a rear view and a left-side view, respectively, showing a key-coupler according to the present invention;

[0013]FIGS. 2A and 2B are cross-sectional views showing the key-coupler, taken along lines IIA-IIA and IIB-IIB, respectively, shown in FIG. 1B;

[0014] FIGS. 3A-3C are perspective views showing the key-coupler, illustrating a process of coupling a key with a key-holder via the key-coupler;

[0015] FIGS. 4A-4D are a front view, a top view, a rear view and a left-side view, respectively, showing a modified form 1 of the key-coupler;

[0016]FIGS. 5A and 5B are cross-sectional views showing the modified form 1, taken along lines VA-VA and VB-VB, respectively, shown in FIG. 4B;

[0017] FIGS. 6A-6D are a front view, a top view, a rear view and a left-side view, respectively, showing a modified form 2 of the key-coupler;

[0018]FIGS. 7A and 7B are cross-sectional views showing the modified form 2, taken along lines VIIA-VIIA and VIIB-VIIB, respectively, shown in FIG. 6B;

[0019] FIGS. 8A-8D are a front view, a top view, a rear view and a left-side view, respectively, showing a modified form 3 of the key-coupler;

[0020]FIGS. 9A and 9B are cross-sectional views showing the modified form 3, taken along lines IXA-IXA and IXB-IXB, respectively, shown in FIG. 8B;

[0021] FIGS. 10A-10D are a front view, a top view, a rear view and a left-side view, respectively, showing a modified form 4 of the key-coupler;

[0022]FIGS. 11A and 11B are cross-sectional views showing the modified form 4, taken along lines XIA-XIA and XIB-XIB, respectively, shown in FIG. 10B; and

[0023]FIG. 12A is a perspective view showing a conventional key-coupler; and

[0024]FIG. 12B is a perspective view showing another conventional key-coupler.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0025] A preferred embodiment of the present invention will be described with reference to FIGS. 1A-1D, 2A-2B and 3A-3C.

[0026] First referring to FIGS. 1A-1D and 2A-2B, a structure of a key-coupler 10 will be described. Front, top, rear and left-side views of the key-coupler 10 are shown in FIGS. 1A-1D, respectively, but bottom and right-side views are not shown because the bottom view is the same as the top view and the right-side view is the same as the left-side view.

[0027] The key-coupler is made of a single spring wire having a diameter of 1 mm. The key-coupler 10 is composed of a first circular portion 11, a second circular portion 12 and a connecting portion 13 (better understood from FIG. 3B). A first closed ring 10 a is formed by overlapping the first circular portion 11 on the second circular portion 12. A second closed ring 10 b is also formed when the first and the second circular portions 11, 12 are overlapped. The second closed ring 10 b is partially encircled with the connecting portion 13 and positioned between the first closed ring 10 a and the connecting portion 13 (better seen in FIG. 1B).

[0028] The first circular portion 11 is formed in a circular shape having a first opening 11 a, and the second circular portion 12 is formed in the same circular shape having a second opening 12 a. Both openings 11 a, 12 a are positioned symmetrically with respect to a center line IIA-IIA (shown in FIG. 1B) when both circular portions 11, 12 are overlapped. In forming the first circular portion 11, one end of the spring wire is wound counter-clockwise by 315°. The second circular portion 12 is formed by winding the other end of the spring wire clockwise by 315°.

[0029] The first opening 11 a is closed by the second circular portion 12 and the second opening 12 a is closed by the first circular portion 11 when both circular portions 11, 12 are overlapped. Thus, the first closed ring 10 a is formed. The second closed ring 10 b encircled with the connecting portion 13 is also formed when the first and the second circular portions are overlapped.

[0030] When the first and the second circular portions are forcibly separated, the first and the second openings 11 a, 12 a are opened, and thus the first closed ring 10 a are opened. The second closed ring 10 b is also opened at the same time when the first and the second circular portions are separated. When the force forcibly separating both circular portions 11, 12 is released, both the circular portions 11, 12 return to their initial positions by the spring-back force of the spring wire, thereby contacting each other. Thus, the first closed ring 10 a and the second closed ring 10 b are formed again.

[0031] Now, referring to FIGS. 3A-3C, a process of coupling a key 20 with a key-holder 25 via the key-coupler 10 will be described. The key-coupler 10, to which no external force is applied and nothing is connected, is shown in FIG. 3A. The first circular portion 11 and the second circular portion 12 are forcibly separated from each other as illustrated in FIG. 3B with exaggeration. That is, by applying external force, the first closed ring 10 a and the second closed ring 10 b are opened at the same time. A key 20 (or plural keys) is coupled in the second closed ring 10 b by inserting the key 20 through the opening between both circular portions 11, 12. A key-holder 25 (or a key-holder ring) is similarly coupled in the first closed ring 10 a. By releasing the force forcibly separating the circular portions 11, 12, the key-coupler 10 returns to its original shape by its spring-back force, as illustrated in FIG. 3C. The key 20 may be coupled with the second closed ring 10 b by connecting a hole 21 of the key 20 to the second closed ring 10 b. Thus, the key 10 (or keys) is coupled with the key-holder 25 via the key-coupler 10.

[0032] The key-coupler 10 described above is easily opened by separating the first circular portion 11 from the second circular portion 12, and the key 20 and the key-holder 25 can be easily engaged with the second closed ring 10 b and the first closed ring 10 a, respectively. It is not necessary to turn the key 20 after it is inserted into the key-coupler 10. By simply releasing the separating force, the key-coupler 10 returns to its original shape by its own spring-back force, thereby surely holding the key 20 in the second closed ring 10 b and the key-holder 25 in the first closed ring 10 a.

[0033] The key 20 and the key-holder 25 are easily disconnected from the key-coupler 10 by simply separating the first circular portion 11 from the second circular portion 12. In addition, since the first closed ring 10 a and the second closed ring 10 b are positioned on the substantially same plane, the key-coupler 10 can be made thin and compact in size.

[0034] The present invention is not limited to the embodiment described above, but it may be variously modified. Some modified forms will be described below. A key-coupler 30 as a modified form 1 is shown in FIGS. 4A-4D and 5A-5B. In the modified form 1, a first closed ring 30 a is formed in a triangular shape having round corners (changed from a circle shape) as shown in FIG. 4B. Other structures and functions of the modified form 1 are the same as those of the key-coupler 10 described above. Reference numbers used in the key-coupler 10 correspond to reference numbers used in the modified form 1 as follows: key-coupler 10→30; first circular portion 11→31; second circular portion 12→32; first closed ring 10 a→30 a; second closed ring 10 b→30 b; first opening 11 a→31 a; second opening 12 a→32 a; and connecting portion 13→33.

[0035] A key-coupler 40 as a modified form 2 is shown in FIGS. 6A-6D and 7A-7B. In this modified form 2, a first closed ring 40 a is formed in a triangular shape having round corners (same as the modified form 2) as shown in FIG. 6B. In addition, a second closed ring 40 b is shaped in a trapezoidal shape (changed from a round shape). Other structures and functions of the modified form 2 are the same as those of the key-coupler 10 described above. Reference numbers used in the key-coupler 10 correspond to reference numbers used in the modified form 2 as follows: key-coupler 10→40; first circular portion 11→41; second circular portion 12→42; first closed ring 10 a→40 a; second closed ring 10 b→40 b; first opening 11 a→41 a; second opening 12 a→42 a; and connecting portion 13→43.

[0036] A key-coupler 50 as a modified form 3 is shown in FIGS. 8A-8D and 9A-9B. In this modified form 3, a first circular portion 51 is formed to include an angled portion 51 b, and a second circular portion 52 is formed to include an angled portion 52 b. As better seen in FIG. 8D, both angled portions 51 b, 52 b form a gap 50 c therebetween when both circular portions 51 and 52 are overlapped with each other. Since the gap 50 c is formed in this modified form 3, the circular portions 51, 52 can be easily opened by simply pushing a back of the key 20 against the gap 50 c. Therefore, the key 20 is easily coupled with the key-coupler 50. The key-holder 25 can be easily coupled with the key-coupler 50 in the same manner.

[0037] Other structures and functions of the modified form 3 are the same as those of the key-coupler 10 described above. Reference numbers used in the key-coupler 10 correspond to reference numbers used in the modified form 3 as follows: key-coupler 10→50; first circular portion 11→51; second circular portion 12→52; first closed ring 10 a→50 a; second closed ring 10 b→50 b; first opening 11 a→51 a; second opening 12 a→52 a; and connecting portion 13→53.

[0038] A key-coupler 60 as a modified form 4 is shown in FIGS. 10A-10D and 11A-11B. This modified form 4 is similar to the modified form 3 described above except for the position of a gap 60 c. In the modified form 3 described above, the gap 50 c is positioned at a side opposite to the second closed ring 50 b. In this modified form 4, a gap 60 c is positioned at a side facing the second closed ring 60 b, as better seen in FIG. 10D. A first circular portion 61 is formed to include an angled portion 61 b, and a second circular portion 62 is formed to include an angled portion 62 b. As shown in FIG. 10D, both angled portions 61 b, 62 b form a gap 60 c therebetween when both circular portions 61 and 62 are overlapped with each other. Since the gap 60 c is formed, the circular portions 61, 62 can be easily opened by simply pushing a back of the key 20 against the gap 60 c. Therefore, the key 20 coupled to the key-coupler 60 is easily removed therefrom. Also, the key-holder 25 coupled to the key-coupler 60 can be easily separated therefrom in the same manner.

[0039] Other structures and functions of the modified form 4 are the same as those of the key-coupler 10 described above. Reference numbers used in the key-coupler 10 correspond to reference numbers used in the modified form 4 as follows: key-coupler 10→60; first circular portion 11→61; second circular portion 12→62; first closed ring 10 a→60 a; second closed ring 10 b→60 b; first opening 11 a→61 a; second opening 12 a→62 a; and connecting portion 13→63.

[0040] The present invention is not limited to the embodiment and its modified forms described above, but it may be further modified. For example, the key 20 may be coupled with the first closed ring 10 a instead of the second closed ring 10 b. Similarly, the key-holder 25 may be coupled with the second closed ring 10 b. In this manner, the key 20 (or keys) is coupled with the key-holder 25 via the key-coupler 10. Though the key-coupler is integrally made of a single spring wire in the embodiment described above, the key-coupler can be made by connecting the first and the second circular portions, which are separately made, with the connecting portion made of a spring material.

[0041] While the present invention has been shown and described with reference to the foregoing preferred embodiment and its modified forms, it will be apparent to those skilled in the art that changes in form and detail may be made therein without departing from the scope of the invention as defined in the appended claims. 

What is claimed is:
 1. A key-coupler for coupling a key to a key-holder, the key-coupler comprising: a first circular portion; a second circular portion; a connecting portion connecting the first circular portion to the second circular portion; a first closed ring formed by overlapping the first circular portion with the second circular portion; and a second closed ring defined by the connecting portion and the first closed ring, the second closed ring being formed by overlapping the first circular portion with the second circular portion, wherein: the first closed ring and the second closed ring are opened by applying a force forcibly separating the first circular portion from the second circular portion, and both rings are closed by removing the forcibly separating force.
 2. The key-coupler as in claim 1, wherein: the first circular portion includes a first opening that is closed by the second circular portion when both circular portions are overlapped with each other; and the second circular portion includes a second opening that is closed by the first circular portion when both circular portions are overlapped with each other.
 3. The key-coupler as in claim 2, wherein: the connecting portion is made of a material having a spring action.
 4. The key-coupler as in claim 2, wherein: the first circular portion, the second circular portion and the connecting portion are all integrally made of a single spring wire.
 5. The key-coupler as in claim 4, wherein: the first and the second circular portions include respective angled portions that form a gap therebetween when both circular portions are overlapped with each other.
 6. The key-coupler as in claim 4, wherein: both of the first closed ring and the second closed ring are formed so that both rings are positioned substantially on a same plane.
 7. The key-coupler as in claim 6, wherein: the first ring is formed in a circle shape on the plane.
 8. The key-coupler as in claim 6, wherein: the first ring is formed substantially in a triangular shape on the plane.
 9. The key-coupler as in claim 8, wherein: the second ring is formed substantially in a trapezoidal shape on the plane.
 10. The key-coupler as in claim 5, wherein: the gap is formed on the first closed ring at a position opposite to the second closed ring.
 11. The key-coupler as in claim 5, wherein: the gap is formed on the first closed ring at a position facing the second closed ring. 